1. Technical Field
The present invention relates to a method for measuring curvature of an optical fiber.
2. Related Art
When laying optical fibers for communication, the optical fibers can be connected by a fusion splicer. When the connected optical fibers are bent, the axial cores of a portion held in a V-groove and a tip of a portion held at one end can become skewed, and this increases loss at the spliced region.
Therefore, the curvature radius of an optical fiber is set to be 2 meters or more, and the curvature radius of ribbon cable, which is easily affected by curvature, is set to be 4 meters or more (Non-Patent Document 1). Methods for measuring the curvature or curvature radius of an optical fiber include side view microscopy and laser beam scattering, for example (Non-Patent Document 2).    Non-Patent Document 1: IEC 60793-2-50, Edition 3.0 2008-05, Optical fibres—Part 2—50: Product specifications—Sectional specification for class B single mode fibres    Non-Patent Document 2: IEC 60793-1-34, Optical fibres—Part 1—34: Measurement methods and test procedures—Fibre curl.
However, when repeating the curvature measurement of the optical fiber, there is a large variation for the curvature in the longitudinal direction.